I have a TH350 Trans but it kicks is too hard when changing gears, the previous owner said there is an adjuster that i can adjust with a flat head so it does not shift so hard. anyone heard of this before or have any pointers on how to reduce this when shifting.?

anyone have any advice or know about transmissions?. why it would do this?

The vacuum modulator is probably adjustable. Pull the vacuum hose off the transmission connection and a small Allen wrench fits into the nipple where the hose was. back it off a full turn at a time and see how it shifts. That may an easy first attempt.